Mr Robinson, the broadcaster?s Political Editor, reported the claims on the BBC?s flagship 6pm news bulletin on Wednesday evening.

Speaking hours after the machete attack, and just minutes before the programme, Mr Robinson said he was told by ?a senior Whitehall source that the incident was being treated as a suspected terrorist incident and being taken very seriously indeed?.

He continued: ?This information changed the news from a crime story to something of more significance.

?The police had, I was told, described the attackers as being ?of Muslim appearance? and shouting ?Allahu Akbar?. On air I directly quoted a senior Whitehall source saying that the police had used that description.?

However in a 380-word blog on his website on Thursday, Mr Robinson apologised and said he now regrets using the expression!